GSSL HELP THREAD!!!

[timmygrimm]

Hi All,

I just stuffed my first SSL clone. It's one of my first DIY-deals. Thank you very much to Jakob and the rest of you for making this possible!

I seem to be having a problem with my 7915 - I'm showing -24v (where -15 should be) all around the board and at the output of the 7915. The input of the 7915 is showing -24.

The +15,+12 and -12 are all cool. I checked the 10r resistors (my best guess?!) around the 7915 - and they check out.

I'm thinking it's a bad regulator, but I wanted to check here before I went out and bought another one. I must admit I acidentally shorted the 7915 for a second with a test probe and it sparked. Would that be enough to ruin it?

Thanks again,

Tim

 

[gyraf]

I'm thinking it's a bad regulator, but I wanted to check here before I went out and bought another one. I must admit I acidentally shorted the 7915 for a second with a test probe and it sparked. Would that be enough to ruin it?

Bad regulator it is - and yes, a short is enough to kill it. Replace.

Jakob E.

 

[timmygrimm]

Well, she's passing clean audio and the makeup gain works, but no compression or meter activity with com+on connected.

Is it possible that I oriented the lorlins the wrong way? Somebody was asking somewhere in this thread and I wasn't sure of the answer.

I don't have an oscilloscope, so I don't know if that rules out the possibility of tracing signal... or maybe I need to trace control voltage? hmm...

I will continue to dig in this thread, but if anyone has suggestions i'd appreciate it!

UPDATE : working! sweet. Point d had no continuity to the control pcb... that would do it!

it works great... much more subtle than i would have guessed. i've worked with the real thing before and it seemed a bit more prominent, but i'm not sitting right in front of the speakers (or in a control room for that matter!) so that might make a difference!

Thanks for a great project!... now if I didn't have to deal with the lips on my par-metal case!

Tim

 

[Fredrik]

Does anybody know where I can find the eao series 01 switch, preferably in eu? :roll:

 

[timmygrimm]

So upon further investigation it seems all is not perfectly well in SSL land.


My left and right channels are not equal gain wise, even with the unit in bypass. If I send a 1khz test tone through the gssl (in bypass) I get

- 8 db on the left channel
+6 db on the right channel

I'm using a computer to meter... the tests aren't very exact but generally speaking the left channel is less than unity and the right is greater.

If I run a signal through one channel at a time, they will both trigger compression to the same degree, which to me rules out the input stage (?).


Could anyone suggest a test I could perform with a multimeter (no oscilloscope) to figure out where the problem lies? All my IC power readings check out, and I've tried swapping input, output ICs and VCAs.

Thanks!

Tim

 

[keefaz]

Your computer audio interface inputs are balanced ?
Are your input/output XLR to PCB connections ok ?

 

[timmygrimm]

Thanks for the reply,

I am using a Digi 002 rack - balanced 1/4" input.

I tested the cables by jumpering (with probes) the input to the output directly. It exhibits no loss (or gain :grin when I do that, so I have kind of ruled out the cabling. I will reheat all those solder joints though just to make sure. The gain on the right channel seems to not point in that direction as well.

Tim

 

[josh]

hello.
I looked in other threads and didnt see an answer, and there's no way I'm skimming 100+ pages of this thread, so please bear with me.

The front Lorlin switches that mount directly into the pcb...
2 of them can be mounted in 2 positions. Does it matter which way they go? Then the other can be mounted 4 ways, same thing?

The release is (from what I've gathered) to be converted form a 2 x 6 to a 2 x 5. Now, I've seen a picture of someone holding a knife to the side of the switch and the caption explaining this is what is happening, but I have yet to locate an actual description of the procedure involved in this. Anyone care to elaborate?

Lastly, is there a general sort of "off board wiring" document available for this? I have never wired an XLR jack before, and it took me about an hour to finally locate a thread where someone explains in detail how to connect the transformer.

 

[flight]

Hello ,

-My clone is finished but i experience a strange thing when turning the relese to 0.6 . It seems to down the threhsold from few db ( and this only occur at 0.6 release )
I ve checked cap and resistance at this point but all seems good any idea ?

Thanks

 

[timmygrimm]

[quote author="josh"]
The front Lorlin switches that mount directly into the pcb...
2 of them can be mounted in 2 positions. Does it matter which way they go? Then the other can be mounted 4 ways, same thing?[/quote]

I just threw my lorlins in there and they work fine.

XLRs are wired:

Pin 1 - ground (l+r share the middle pin on the boards)
Pin 2 - +
Pin 3 - -

Th3 5-6 position switch conversion is in the first few pages of this thread i believe. It was easy to find.

 

[obostic]

Does anyone know when calibrating the GSSL for unity gain should the voltage be measured across pin 1&2 or pin 2&3?

The reason I'm asking is because with my unit calibrated for unity using pin 2&3 the GSSL is dropping in level when feed music with no apparent compression. The odd thing is that when using a 1KHz sine wave their is no difference between the levels whether bypassed or not.

By the way, In compressor mode with the threshold is set fully CW, the audio drops approximately 6-8dBs then the original bypassed signal level. I am using THAT2180LC with the suggested mods in the Emulation section and a true bypass. Also, the 15K resistors were replaced with 50K trim pots with a final setting of 29K, and the 47K resistors replaced with sidechain mod.

 

[gyraf]

..depends on balanced/unbalanced interfacing - and whether the previous balancing is transformer or not..

 

[obostic]

Hi Gyraf,

Thanks for your response. The unit is connected between my 1/2" tape machine and console for testing purposes.

The tape machine output is +4dBu low impedance, balanced(600 ohm load) into the console tape input, which is unbalanced +4dBu.

What I did find was with the trim pot set to 15K their is no loss of signal. I'm just trying to get my hand around the design and want be sure that the unit is working correctly.

Thanks,

 

[gyraf]

The unit is working correctly if you can get it to compress and get 0dB gain through it in bypass..

Jakob E.

 

[dinesh]

Hi,

Can we use 6.8uf /35 V & 0.47uf/35V Tantalums in SSL MixBuss?

 

[PTMIX]

Hello,

First off this forum rocks and i'm very excited to be a newbie sponge in here. Also thanks to gyraf & everyone here for making this project possible. I've been taking my time (slow) doing this project, testing all resistors and caps before soldering in-place, also my soldering skills are very good, as i'm new to DIY, but i've been making cables and such for 4/5 years... I've been reading all of this "help forum" for awhile and can't seem to figure out what is wrong with my board, so sorry if it's been answered before!!

The problem...
board passes audio, but is always distorted with normal levels!! also the threshold seems to kinda work, but also seems like it's a volume control as well?!?!? makeup gain works but again it just distorts more when i pull the vol up...

here is some info on what i've measured, wondering if there is something wrong with rails, or IC's as i feel this is not a loose solder point or wrong component.

thres & makeup pot is ccw on all measurements

Output (Left) NE5532AP
PIN 4: -15.5 vdc
PIN 8: 14.9 vdc

Output (Right) NE5532AP
PIN 4: -15.5 vdc
PIN 8: 14.9 vdc

Input (Left) NE5534AP
PIN 1: 12.39 vdc
PIN 4: -15.5 vdc
PIN 7: 14.9 vdc
PIN 8: 12.41 vdc

Input (Right) NE5534AP
PIN 1: 12.27 vdc
PIN 4: -15.5 vdc
PIN 7: 14.9 vdc
PIN 8: 12.4 vdc

VCA (Left) NE5534AP
PIN 1: 12.24 vdc
PIN 4: -15.06 vdc
PIN 7: 14.9 vdc
PIN 8: 12.25 vdc

VCA (Right) NE5534AP
PIN 1: 12.17 vdc
PIN 4: -15.3 vdc
PIN 7: 14.9 vdc
PIN 8: 12.2 vdc

TL072
PIN 1: -3.06 vdc
PIN 4: -12.3 vdc
PIN 8: 12.6 vdc

Thanks in advance for anyones help, also again Gyraf & Others, the amount of time that is spend helping ppl like me is amazing, it's very evident with your replies.. Someday i hope to be able to give back even tho i think i'm pressed to even give back 1/10th what you ppl have given to me!!!

THANKS,

~J~

 

[PTMIX]

Anyone???

Thanks,

~J~

 

[radiance]

I don't know about these voltages and pins and what they should be but what you can try is the following.
Pull out both main VCA's and connect pin 1 with pin 8. This way you only test the in and output section. If it passes audio OK you know the problem is else where, probabely in the side chain department....

 

[kryckmeister]

My SSL sounds normal when bypassed. When it's activated it's distorting everything very disgustingly, but apart from that it has some weird behavior.

When threshold is brought down, almost to the bottom and down(maximum compression) my Behringer meter starts hitting the maximum value like 60bpm at 2:1, and strikes harder when ratio is increased to 4:1 and 10:1.

Any ideas of what to start looking for and where?

 

[Greg]

I'd suspect control board wiring. Don't even look at the thing tonight, and see what you can find tomorrow.